Supercapacitors, electrically active polymers

In order to satisfy the industrial demand, the performance of supercapacitors must be improved and new solutions should be proposed. The development of new materials and new concepts has enabled important breakthroughs during the last years. In this forecast, carbon plays a central role. Due to its low cost, versatility of nanotextural and structural properties, high electrical conductivity, it is the main electrode component. Nanoporous carbons are the active electrode material, whereas carbon blacks or nanotubes can be used for improving the conductivity of electrodes or as support of other active materials, e.g., oxides or electrically conducting polymers. 

Conducting polymers such as polyacetylene, polypyrrole, polyaniline, polythiophene, etc. have been actively studied for use in various fields due to their interesting properties batteries,46 electrochromic displays,47 materials for supercapacitors,48 corrosion protection,49 protecting layers for static electricity,50 materials for organic electroluminescence displays,51 sensing materials,52 etc. Polypyrrole is reported to be extremely rigid, with a semi-crystalline structure. 

PPy offers tremendous technological potential, especially as electrodes for rechargeable batteries, sensors or supercapacitors. Since the electrochemical activity of PPy electrodes is proportional to the surface area, they must be processed to a shape in which the ratio of the surface area to volume or weight is high. This feature could be obtained via converting PPy to a fibre with small diameter, i.e., a nanofibre. In the nanoscale, the electrical conductivity of conductive polymers is increased. 

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